1, adhesion, scratch: Due to the material and punch or die friction in the workpiece or die surface appearance of bad;
2, Burr: mainly in the shear and blanking die, the edge of the gap between the big or the hour will produce burrs;
3, line offset: Workpiece forming, the first contact with the mold is squeezed and formed a line;
4, concave and convex: The open Line has foreign bodies (iron filings, rubber, dust) mixed to cause bump;
5, twists and turns: because of uneven stress, poor matching of drawing bar or poor control of the press slider caused by the workpiece R corner or the embossing site twists, strains;
6, wrinkles: Due to poor adjustment of the press slider, low press accuracy, air cushion pressure adjustment unsuitable, punch or R part of large and other causes of the edge or R site wrinkles.
7. Other specific issues: in daily production, will encounter punching size large or small (may exceed the specifications) and with the convex mold size difference between the situation, in addition to taking into account the forming convex, concave mold design size, processing accuracy and blanking clearance and other factors, but also from the following aspects to consider to solve.